Removable platform and load bed for vehicles

ABSTRACT

A movable frame is adapted to be loaded onto and unloaded from a stationary frame mounted on a vehicle. A platform is releasably mountable onto said movable frame. The platform and movable frame may be hoisted simultaneously when being loaded and unloaded from the stationary frame. The platform includes a downwardly depending support legs which are of sufficient length to maintain the platform elevated above a first portion of the movable frame which is inserted under said platform when said movable frame is resting in a lowered position when unloaded from the stationary frame. The movable frame may be raised to engage with the underside of said platform. Interlocks cooperate between said platform and said movable frame so that the movable frame centres onto and mates with said underside of said platform.

FIELD OF THE INVENTION

This invention relates to the field of devices for loading and unloadinga movable frame from a stationary frame mounted on a vehicle, and inparticular to a removable platform and load bed for loading andunloading from a stationary frame on a vehicle wherein, once unloaded,the platform on the movable frame may be detached allowing removal ofthe movable frame from under the platform for re-loading of the movableframe onto the stationary frame.

BACKGROUND OF THE INVENTION

As stated in my Canadian Patent No. 2,434,792 which issued Apr. 13, 2010for a Removable Load Bed for Vehicles, a frame on a vehicle may beadapted for loading and unloading a movable frame therefrom so that forexample the movable frame may be unloaded onto the ground and thereaftermay be loaded up from the ground and onto the stationary frame of thevehicle for transportation of the movable frame and associated load bedmounted thereon. Thus in my previous invention for a removable load bedfor vehicles, I provided an apparatus having a stationary frame and amovable frame that had a flexible connector mounted on the movable framefor releasably engaging a drive on the stationary frame. A lockingsystem was mounted on the stationary frame to hold the flexibleconnector in releasable engagement with the drive. In one embodiment,the flexible connector was a chain and the drive included a drivesprocket. The drive hoisted the movable frame by means of the flexibleconnector onto the stationary frame. The drive engaged the under side ofthe movable frame so as to translate the movable frame along the lengthof the stationary frame with the result that the movable frame waspositioned directly on top of the stationary frame to provide the loadbed mounted on the movable frame as a flat bed for the vehicle. Thus aload mounted onto the load bed could be transported by the vehicle andsubsequently unloaded onto the ground so as to leave the load supportedon the movable frame resting on the ground. Alternatively, the movableframe and bed could be placed onto the ground and a load mountedthereon, whereafter, the movable frame, bed and load could be hoistedonto the stationary frame for transport by the vehicle.

My Canadian Patent No. 2,434,792, and my corresponding U.S. Pat. No.6,857,840 which issued Feb. 22, 2005, are incorporated herein byreference.

What my previous Removable Load Bed for Vehicles invention did notprovide for, and to which the present invention is directed, wasdetaching the load bed from the movable frame when the load bed, whetheror not carrying a load thereon, was mounted on the movable frame and themovable frame unloaded from the stationary frame so as to rest on theground. I realized that, if the load bed was converted to a platformhaving for example legs so that it could stand alone elevated a smalldistance above the ground, I could detach the movable frame fromunderneath the load bed platform, reload the movable frame onto thestationary frame, thereby allowing the vehicle to depart to pickup asecond load bed whether loaded or not, from a different location, wherethe second load bed was also provided as a stand alone platform. Thus,in order to pickup the second load bed platform, the vehicle merely hasto backup to the second load bed platform, unload the movable frame fromthe stationary frame, guide the unloaded movable frame underneath theplatform, secure the movable frame to the platform, and reload themovable frame with the platform mounted thereon back onto the stationaryframe so as thereafter transport the platform. Thus envisioned that sucha movable frame and detachable platform would be useful for a pre-loadedplatform which for example may have loaded thereon the equipmentnecessary for a particular job or jobsite, or may have loaded thereon aportable toilet to be delivered to or moved from a jobsite, or mayinclude a preloaded platform having recreational vehicles ready to goand mounted thereon, for example a pair of ATV's or a pair ofsnowmobiles, all of which may be simply transported and left in adesired location The desired location may be a storage or job site.

The operator may merely leave behind the loaded platforms, withouthaving to leave behind the movable frame as would have been the case inmy previous Removable Load Bed for Vehicles. This allows the movableframe to be re-used to transport other loads on other similar platforms.Pre-loaded platforms may thus be stored ready for use and immediatelytransported when needed at particular locations without delay.Equipment, amenities, small habitats such as so-called micro-houses mayall be pre-configured and pre-loaded onto a platform waiting transportor retrieval, without the need to strand a movable frame with eachplatform.

The adaption of my previous removable load bed for vehicles thusrequired that I sever the movable frame from the load bed, and adapt theload bed to provide a stationary platform. The improvements which thisentailed in order to enable the present invention are both summarizedand described in detail below.

SUMMARY OF THE INVENTION

In summary, the removable platform and load bed according to the presentinvention for a vehicle having a stationary frame, may be characterizedin once aspect as including a movable frame which is detachablymountable to a platform so that the combination of movable frame andplatform may be hoisted and onto the vehicle when stationary vehicle.The movable frame is thus adapted to be loaded onto and unloaded fromthe stationary frame mounted on the vehicle. The movable frame hasopposite front and rear ends. A longitudinal direction ground surfacetranslator such as a roller or slide plate, etcetera, is mounted underthe rear end for translation of the rear end of the movable frame on thetranslator when the translator is in contact with an under-lying groundlevel surface.

The platform may be mountable onto the movable frame and releasablysecured thereon. The platform and movable frame are thus hoistedsimultaneously when being loaded and unloaded from the stationary frame.The platform has front and rear legs. The rear legs are positionedforwardly inset from the rear-most end of the platform bed so as toprovide a pivoting function. In particular, when the front section ofthe movable frame is lifted by the flexible connector and drive on thestationary frame, rails on the movable frame are lifted and contact theunderside of the platform resting on its legs on the ground. As thefront section of the platform is raised on the front section of themovable frame, the rear sections of the platform lower as the platformpivots about the base of the rear legs.

The platform includes a load-bearing deck mounted onto a support frame.Downwardly depending support legs are mounted to the frame. The legs areof sufficient length to maintain the frame and deck by a first distanceelevated above the ground level surface when the legs are resting downof the ground level surface. The movable frame includes a first portionfor insertion under the frame and deck of the platform. The firstportion has a corresponding first height above the ground level surfacewhen the movable frame is resting in a lowered position on thelongitudinal direction ground surface translator and unloaded from thestationary frame. The first height is less than the first distance sothat in the lowered position the movable frame is translatablelongitudinally relative to, and under, the deck and frame of theplatform without obstruction. However, when in a first raised positionthe movable frame engages with an underside of the platform. Theplatform and movable frame further include interlocks cooperatingbetween platform and the movable frame so that when the movable frame isin the first raised position the movable frame centres and mates withthe underside of the platform. The interlocks releasably secure theplatform down onto the movable frame wherefrom the combination may behoisted into a second raised position ready for hoisting the combinationonto the stationary frame. The platform and movable frame are thereaftersecurely hoistable from the second raised position as a unitarycombination onto the stationary frame.

The interlocks may include a first interlock at the front end of themovable frame and a second interlock at the rear end of the movableframe. The first and second interlocks may each include a male componentinterlocking into a female component as the platform bears down onto themovable frame as the movable frame is raised to the first raisedposition from the lowered position.

In one embodiment at least one of the first and second interlocks mayinclude at least one wedge for guiding the male component into thefemale component. For example, each of the first and second interlocksmay include a wedge component. At least one of the wedge componentscentre the platform on the movable frame.

A further centering device may include a pair of flexible substantiallynon-resilient members such as chain, cable, etcetera mountable to, andso as to extend between the frame of the platform and the rear end ofthe movable frame. The pair of members are positioned on directlyopposite sides of the movable frame. The pair of members are adapted totension and, when tensioned, triangulate the rear end so as to centeredbetween laterally opposite sides of the frame of the platform.

The first interlock may include a laterally extending wedge for guidinga laterally extending male member into a laterally extending femalereceiver. The second interlock may include an upstanding wedge on themovable frame engaging upwardly into a correspondingly wedge-shapedfemale receiver on the frame of the platform. The second interlockthereby centres the platform on the movable frame. A lock-down membermay be provided which is releasably mountable to the movable frame andover a front end of the platform when overlaid onto the front end of themovable frame. The lock-down member locks the front of the platform downonto the front of the movable frame. The front end of the movable framemay include at least one rigid upright. The lock-down member may bereleasably securable thereto. The lock-down member may be a laterallyextending elongate member such as a bar.

The female receiver of the first interlock may include a laterallyextending channel formed between the upright(s) and the wedge(s) on thefront end of the movable frame.

At least one hoist engaging member, such as pair of chains, may bemounted at the front end of the movable frame. The hoist engaging memberis adapted to engage a driven hoist such as a hoist having a drivesprocket on the vehicle whereby the movable frame is hoistable onto thestationary frame. The hoist engaging member provides for lowering of themovable frame downwardly into the lowered position and hoistingtherefrom into the first and second raised positions.

The interlocks also include tie-downs. The tie-downs are releasablymountable between the platform and the movable frame. The tie-downs maybe located at the front and rear ends of the movable frame. A tow-membersuch as a further length of chain may be mounted to the upright(s). Thetow member is adapted for releasably mounting to the vehicle. Using thetow member, the vehicle may tow the movable frame from under theplatform. The upright member(s) may include a laterally spaced apartpair of substantially vertical rigid upright members. The tow membersmay be mounted to the upper end of the uprights.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is, in rear perspective view, the vehicle and stationary frame infront of a lowered movable frame resting on the ground.

FIG. 2 is, in rear left side perspective view, a platform according toone embodiment of the present invention resting on the ground with amovable frame inserted underneath the platform with the floor plankingon the left side of the platform removed.

FIG. 3 is in upper left side rear perspective view, the forward end ofthe platform and movable frame of FIG. 2 showing the locking barelevated and temporarily suspended from the top of the protective wallby a pair of chains, and showing the platform disengaged from themovable frame and the movable frame having been pulled slightly forwardfrom its insertion underneath the platform.

FIG. 4 is, in upper left side perspective view, the platform and movableframe of FIG. 3 with the locking bar removed and the movable frameslightly further advanced forwardly from underneath the platform.

FIG. 5 is, in upper left side rear perspective view, a portion of thefront ends of the movable frame and platform of FIG. 2 showing the frontend of the platform mated down onto the movable frame.

FIG. 6 is, in upper rear left side perspective view, the mating of thefront end of the platform onto the front end of the movable frame ofFIG. 5 showing the locking bar suspended on a pair of lengths of chainabove the front end of the platform awaiting lowering into lockingengagement down against the front end of the platform.

FIG. 7 is, in left side elevation view, the front end of the platformmounted onto the front end of the movable frame, and showing a portionof the hoisting chain extending upwardly from the front end of themovable frame.

FIG. 8 is, in left side front perspective view, the platform and movableframe of FIG. 5 with the front end of the platform and movable frameelevated to the height of the stationary frame on the vehicle.

FIG. 9 is, in front left side upper perspective view, the tow chainsextending between the front end of the movable frame and the rear end ofthe stationary frame ready for towing the movable frame out fromunderneath the platform.

FIG. 10 is, in lower rear left side elevation view, the underside of theplatform and the rear of the movable frame, with a centering cablemounted between the side of the platform and the side of the movableframe.

FIG. 11 is, in upper front left side elevation view, the end of thecentering cable of FIG. 10 where it is attached to the rear end of themovable frame.

FIG. 12 is, in top perspective view, the end of the centering cablewhere it is mounted to the side frame member of the platform.

FIG. 13 is, in partially cut-away left side elevation view, the movableframe in a horizontal position as it would appear resting on top of thestationary frame, and being translated rearwardly by the drive pulleyson the rear of the stationary frame.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention includes two basic components; namely, a movableframe 10 and a platform 12 adapted to be releasably and securely mountedonto the movable frame 10. Movable frame 10 is adapted to be loaded andunloaded onto the stationary frame on a vehicle such as for example bythe mechanism described in my Canadian Patent 2,434,792 or my U.S. Pat.No. 6,857,840 both entitled Removable Load Bed for Vehicles,collectively herein my “previous patents”, and as described above.

Thus in one embodiment, which is not intended to be limiting, astationary frame 14 is mounted rigidly onto, so as to form part of, avehicle 16 which advantageously is a truck, and where the stationaryframe 14 of the vehicle is advantageously mounted behind the truck cab.A hoist or winch arrangement or preferably the loading arrangement,described in detail in my previous patents loads and unloads movableframe 10 from stationary frame 14. Such a loading arrangement may employa drive at the rear end of the stationary frame, and in particular mayinclude a pair of drive sprockets 18 which raise and lower the movableframe by means of a flexible connector such as a pair of chains 20. Thedrive sprockets 18 also advantageously engage a toothed rail 22 allowingthe underside of the movable frame to be selectively translatedlongitudinally relative to the stationary frame of the vehicle.

In one embodiment, which is not intended to be limiting, platform 12 maybe a relatively inexpensive wooden assembly consisting of an outer framehaving side members 24, cross members 26 and floor boards 28. In apreferred embodiment, ply-wood sheeting is mounted underneath floorboards 28 so as to snugly fit between the cross members 26 to therebyreinforce the frame work. A pair of vertically adjustable forward legs30 are slidably mounted through corresponding apertures formed withinblocking 32 mounted or formed between the forward cross members 26′ andthe next adjacent cross members 26. Forward legs 30 are verticallyadjustable by the use of removable pins 34 journalled through apertures30 a. Apertures 30 a are formed as a vertically linearly spaced apartarray of such apertures in forward legs 30. The rear of platform 12 maybe supported on a pair of fixed rear legs 36 mounted to outer framemembers 24. The rear legs are positioned forward of the rear of theplatform. When the front section 10 a of the movable frame 10 is liftedby the turning sprocket 18 and lift chain 20, the movable frame rails 22contact and lift upwardly under the platform 12 and cross member 26causing the rear section 10 b of the platform to lowers, with the pivotpoint of the platform being the base of the rear legs 36 where they arein contact with the ground. The use of the pivot about the inset rearlegs reduce the length of the movement arm and this reduces the requiredmovement to pivot and lift heavy loads on the platform, as compared tomerely pivoting the entire platform upwardly about the very end of theplatform, for example entirely about roller 44. The use of the insetrear legs as a pivot also reduces the bowing of the platform under heavyloading.

The front edge 12 a of platform 12 has a laterally spaced apart pair ofnotches 12 b formed therein. Notches 12 b are spaced apart sufficientlyin size so as to snugly mate with the vertical uprights 38 mounted onthe front end of movable frame 10 as better described below.

Movable frame 10 includes a parallel pair of side rails 40 supportingrigidly mounted cross members 42 mounted laterally thereover so as toprovide a rigid rectangular frame. Longitudinally extending toothedrails 22 extend parallel to side rails 40 and extend from the front end10 a of movable frame 10 to substantially the rear end lob. A roller 44is rotatably mounted below the rearmost cross member 42′ so as to bemedially disposed between the rearmost ends of side rails 40. Roller 44and rolls on contacts the ground as movable frame 10 is unloaded indirection A as seen in FIG. 13 from stationary frame 14. As the frame 10is lowered rear legs contact the ground and the frame then pivotsdownwardly about the rear legs.

As stated above, vertical uprights 38 are rigidly mounted to the frontend 10 a of movable frame 10, and in particular, are spaced apartlaterally so as to be substantially in line with side rails 40. In oneembodiment (not shown) a laterally extending cross member is rigidlymounted across the top ends of vertical uprights 38. In anotherembodiment, instead of use of a cross member, a vertical uprights 38 aremounted to a end-wall 46 which provides vertical uprights 38 withlateral stability and which protects the back of the truck cab whileloading of platforms 12 when used as a conventional flat-bed. Withplatform 12 mounted on movable frame 10, vertical uprights 38 fit snuglyinto notches 12 b along front edge 12 a. Front cross member 26′ seatssnugly down onto rails 22 guided by a sixty degree incline on guidingwedges 48 mounted onto the top of rails 22. The use of a sixty degreeincline is not intended to be limiting as other angles would work solong as centering cables 60 are of appropriate length so that platform12 is urged down onto frame 10. With the front end of platform 12 thussnugged down onto rails 22, a locking plate 50 is lowered down onto thefront decking plank 28′ and secured as by bolting to vertical uprights38 to thereby lock the front end of platform 12 down onto movable frame10 and in particular down onto rails 22. Simultaneously, the rear end ofplatform 12, and in particular rear cross member 26″, also seat snuglydown onto movable frame 10 so as to engage a slanted-end auxiliary crossmember 26 a, and in particular the slanted innermost end of auxiliarycross member 26 a, so as to guide and center rear cross member 26″ ontoeach of a pair of laterally outwardly disposed rigid centering wedges 22a mounted on the laterally outer sides of rails 22. Thus with uprights38 engaging in notches 12 b and the pair of auxiliary cross members 26 aengaging down onto the corresponding pair of centering wedges 22 a,platform 12 is centered when dropping down onto movable frame 10.

With platform 12 so resting on movable frame 10, platform 12 may bereleasably secured to movable frame 10 by many conventional means whichwould be known to one skilled in the art as for example and withoutintending to be limiting by means of shackled chains 52 which releasablymount for example by the use of pinned shackles to the front edge 12 aof platform 12 and at their opposite ends to the side of verticaluprights 38 on movable frame 10. Likewise, the rear end of platform 12may be secured to the rear end of movable frame 10 by the use ofshackles 54. Rear shackles 56 may be used by an operator to assisttethering a load onto a platform 12. Chains 54 a extend between the rearend of movable frame 10 where they are mounted, upwardly to shackles 54mounted on the rear end of platform 12.

When for example it is desired to leave a load at work site, and theload is being transported to the work site on platform 12 by vehicle 16,and once movable frame 10 with platform 12 mounted thereon has beenunloaded from the vehicle once it arrives at the job site, it may bethat the operator may desire to leave the load on platform 12 but wouldlike to retrieve movable frame 10 so as to load it back up ontostationary frame 14 to thereby free the operator to fetch another loadmounted on another platform 12. Thus once at the job site, the platform12 to be left along with its corresponding load is unloaded fromstationary frame 14 so as to leave platform 12 resting on the ground onlegs 30 and 36. Vertical legs 30 may have to be elevated as thecombination of platform 12 mounted on movable frame 10 as they are beingeither loaded or unloaded from stationary frame 14 so that the lowermost ends of legs 30 do not catch on the rear tires of vehicle 16.

Thus with platform 12 resting down on the ground on legs 30 and 36,shackled chains 52 as seen in FIG. 8 may be released and shackles 54released from chains 54 a as seen in FIG. 2, so that movable frame 10may be further lowered relative to the underside of platform 12 oncelocking plate 50 has been unbolted from uprights 38 and removed. Thefurther lowering of movable frame 10 disengages the notches 12 b and thefront cross member 26′ from their position seated between verticaluprights 38 and inclined guiding wedges 48. In the illustrations lockingplate 50 is shown removed and conveniently stored suspended by lengthsof chain from the top of wall 46. As movable frame is further lowered torelease it from coupling under platform 12, the rear end of movableframe 10 and in particular wedges 22 a are released from their matingengagement against the inner most ends of auxiliary cross members 26 a.

With movable frame thus lowered so as to be free of the underside ofplatform 12, pull chains 46 a mounted to the forward side of wall 46 areattached to the rear end of stationary frame 14, for example, by slidingone of the links of each of chains 46 a into correspondingly sized slots14 a formed for example at the rear of stationary frame 14 adjacentdrive sprockets 18. With movable frame 10 thus releasably connected tothe rear end of stationary frame 14, vehicle 16 may be pulled ahead tothereby extract movable frame 10 rolling on roller 44 out fromunderneath platform 12. Once movable frame 10 is clear of platform 12,movable frame 10 may be loaded onto stationary frame 14 for transport.This then leaves behind a relatively inexpensive platform 12 with adesired load at a desired location where the load may be put to use forexample at a job site or place of recreation, etcetera. The movableframe can be pulled out, and the truck can then be driven and turned,backed up and with the movable frame aligned with a second platform andbacked under the second platform without loading the movable frame ontothe truck, thereby saving valuable time when simply swapping platformsat the same job site. The pull chains 46 a ties the movable frame to thetruck, unlike an extension of the truck frame.

It may be that various loads will need to be moved from job site to jobsite for example if a particular load includes a portable toilet, thetoilet will have to be removed for cleaning and replaced. Thus it isdesirable that the reloading of a platform 12 onto movable frame 10 beuncomplicated, and it is an object of the present invention to providethat.

Thus when an operator desires to reload a platform 12 which has beenleft the operator in vehicle 16 pulls up in front of platform 12 leavinga sufficient distance between vehicle 16 and the front end of platform12 so that movable frame 10 may be unloaded fully from stationary frame14. Movable frame 10 is then unloaded from stationary frame 14 so as toposition movable frame 10 on the ground with the front end 10 a adjacentthe rear end of stationary frame 14 and connected thereto by means ofconnector chains 20, and with rear end 10 b of movable frame 10positioned in front of the front end of platform 12. Movable frame 10has been lowered to its lowered position immediately above the ground sothat it may be pushed rearwardly under platform 12 as vehicle 16 drivesin reverse.

To assist the operator with the initial alignment of movable frame 10 asit translates rearwardly on roller 44 underneath platform 12, a pair ofupstanding guide rods (not shown) may be mounted into correspondingapertures in front floor board 28′ so that, with the guide rods markingthe positions of uprights 38 and rails 22 the operator will be able toapproximately align movable frame 10 under platform 12. Once movableframe 10 is approximately three quarters of the way underneath platform12, the operator attaches centering lines 60, which may be cables,chains or the like, between side rail members 24 on platform 12 andwedges 22 a on movable frame 10. With a centering line so attached oneither side of the rear end 10 b of movable frame 10, as the operatorthen continues to insert movable frame 10 underneath platform 12, thelines 60 tighten and triangulate to center the rear end 10 b positionedcentered underneath the rear cross member 26″.

With movable frame 10 thus positioned and centered underneath platform12 the drive on the rear end of stationary frame 14, and in particulardrive sprocket 18 tensioning connector chains 20, may be employed toelevate movable frame 10 so as to once again seat notches 12 b downagainst uprights 38 thereby seating cross member 26′ snugly down wedgedbetween guiding wedges 48 and uprights 38, and so as to also snugauxiliary cross members 26 a down onto wedges 22 a. The shackles maythen be secured by the operator to secure platform 12 down onto movableframe 10. Thereafter movable frame 10, carrying platform 12 and the loadon platform 12 may be loaded onto stationary frame 14 for transport.

Centering lines 60 do not have to be uncoupled when it is desired toremove movable frame 10 out from underneath platform 12 if, as seen inthe preferred embodiment, end 60 a of centering lines 60 are releasablymounted into side rail members 24 for example by use of rings 60 bhooked onto forwardly projecting studs 60 c.

As will be apparent to those skilled in the art in the light of theforegoing disclosure, many alterations and modifications are possible inthe practice of this invention without departing from the spirit orscope thereof. Accordingly, the scope of the invention is to beconstrued in accordance with the substance defined by the followingclaims.

What is claimed is:
 1. A method of coupling a platform to a movableframe, the method comprising: raising a front end of the platform,wherein raising the front end of the platform comprises lowering a rearend of the platform onto a rear end of the movable frame, whereinlowering the rear end of the platform onto the rear end of the movableframe comprises interlocking the rear end of the platform with the rearend of the movable frame.
 2. The method of claim 1 wherein interlockingthe rear end of the platform with the rear end of the movable framecomprises interlocking a male component into a female component.
 3. Themethod of claim 1 wherein interlocking the rear end of the platform withthe rear end of the movable frame comprises interlocking an upstandingwedge on the movable frame into a correspondingly wedge-shaped femalereceiver on the platform.
 4. The method of claim 1 further comprisinginterlocking a front end of the platform with a front end of the movableframe before raising the front end of the platform.
 5. The method ofclaim 4 wherein interlocking the front end of the platform with thefront end of the movable frame comprises interlocking a male componentinto a female component.
 6. The method of claim 4 wherein interlockingthe front end of the platform with the front end of the movable framecomprises causing a laterally extending female receiver to receive alaterally extending male member.
 7. The method of claim 4 whereininterlocking the front end of the platform with the front end of themovable frame comprises causing a laterally extending wedge to guide alaterally extending male member into a laterally extending femalereceiver.
 8. The method of claim 1 wherein raising the front end of theplatform comprises pivoting the platform.
 9. The method of claim 8wherein pivoting the platform comprises pivoting the platform aroundrear legs of the platform, the rear legs of the platform positionedforward of a rear edge of the platform.
 10. The method of claim 1further comprising hoisting the movable frame, and the platform coupledto the movable frame, onto a vehicle.
 11. A platform comprising: aplatform body having a front end and a rear end; a means forinterlocking the front end of the platform body with a front end of amovable frame; and a means for interlocking the rear end of the platformbody with a rear end of the movable frame when the front end of theplatform body is raised and the rear end of the platform body is loweredonto the rear end of the movable frame.
 12. The platform of claim 11wherein the means for interlocking the rear end of the platform bodywith the rear end of the movable frame comprises a wedge-shaped femalereceiver on the platform body for receiving a corresponding upstandingwedge on the movable frame.
 13. The platform of claim 11 wherein themeans for interlocking the front end of the platform body with the frontend of the movable frame comprises a laterally extending female receiverfor receiving a corresponding laterally extending male member on themovable frame.
 14. The platform of claim 11 further comprising a meansfor pivoting the platform body when the front end of the platform bodyis raised.
 15. The platform of claim 14 wherein the means for pivotingcomprises rear legs positioned forward of a rear edge of the platformbody.
 16. The platform of claim 15 further comprising front legs. 17.The platform of claim 16 wherein, when the front and rear legs of theplatform rest on a surface, the front and rear legs hold the platformbody above the surface to receive the movable frame in a space betweenthe platform body and the surface.
 18. A platform comprising: a platformbody having a front end and a rear end; and an interlock at the rear endof the platform body for interlocking with a rear end of a movable framewhen the front end of the platform body is raised and the rear end ofthe platform body is lowered onto the rear end of the movable frame. 19.The platform of claim 18 wherein the interlock at the rear end of theplatform body comprises a wedge-shaped female receiver on the platformbody for receiving a corresponding upstanding wedge on the movableframe.
 20. The platform of claim 18 further comprising an interlock atthe front end of the platform body for interlocking with a front end ofthe movable frame.
 21. The platform of claim 20 wherein the interlockthe front end of the platform body comprises a laterally extendingfemale receiver for receiving a corresponding laterally extending malemember on the movable frame.
 22. The platform of claim 18 wherein theplatform body is pivotable when the front end of the platform body israised.
 23. The platform of claim 18 further comprising rear legspositioned forward of a rear edge of the platform body, wherein theplatform body is pivotable around the rear legs when the front end ofthe platform body is raised.
 24. The platform of claim 23 furthercomprising front legs.
 25. The platform of claim 24 wherein, when thefront and rear legs of the platform rest on a surface, the front andrear legs hold the platform body above the surface to receive themovable frame in a space between the platform body and the surface.